Current Saturation and Steep Switching in Graphene PN Junctions using Angle-dependent Scattering

  • Authors:
    Avik Ghosh (Univ. of Virginia), Mirza Elahi (Univ. of Virginia)
    Publication ID:
    P090237
    Publication Type:
    Paper
    Received Date:
    4-Feb-2017
    Last Edit Date:
    6-Feb-2017
    Research:
    2399.001 (SUNY Polytechnic Institute)

Abstract

Graphene’s ultra-high carrier mobility (200,000cm2/Vs on hBN) makes it promising for high speed applications; however the absence of a band-gap makes it hard to design logic elements out of graphene. It is possible to open a bandgap in graphene by applying strain or by confining it in one direction into nanoribbons, but in the process bandstructure gets distorted near Dirac point and the carrier mobility decreases. A recent set of papers have exploited instead the angle dependent transmission across graphene pn junctions (GPNJ). Since the opening angle is gate tunable, a sequence of angled junctions can turn off the electrons using gateable momentum filtering in the absence of a band-gap (instead, the ideas use a transmission gap). In the absence of edge scattering, momentum filtering is predicted to give large ON, low OFF current and a steep subthreshold swing (SS). In this paper, we calculate the transfer (ID-VG) and output (ID-VD) characteristics of a GPNJ switch and show current saturation using gate geometry alone.

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